The present invention relates to an information recording and reproducing system capable of reproducing information from a recording medium and recording information to a recording medium, more particularly, to a system for controlling information reproduction and recording such that the both are simultaneously performed.
Conventionally, there has been widely used a VTR (video tape recorder) as an information recording and reproducing system capable of both recording and reproducing information such as a moving picture.
The conventional VTR stated above includes a head used to record and reproduce information on/from a video tape.
With the conventional constitution of the VTR, however, information is recorded and reproduced using one head and it is impossible to simultaneously record and reproduce information.
For that reason, if the information which has been recorded so far is to be reproduced from the start, it is necessary to either stop recording information and start reproducing or complete recording all of the information and then to reproduce it.
Considering the need stated above, the applicant of the present invention has already proposed a system for recording and reproducing information in an apparently simultaneous manner as Japanese Patent Application No. 10-9833. In the proposed information recording and reproducing system, image information on a TV program which is recording target information is digitally compressed to generate compressed data, the resultant compressed data is recorded on an optical disc, the compressed data thus recorded is read from the optical disc to be subjected to expansion processing corresponding to the compression processing and the data is outputted as a reproduction signal. In addition, using time to spare while waiting for compression/expansion processing, the recorded position and reproduced position on the optical disc are sequentially searched and recording/reproducing processing is performed, thereby realizing a function of apparently simultaneously recording and reproducing information. The proposed information recording and reproducing system makes it possible to reproduce the recorded TV program from time shifted from the recording start time by a predetermined period of time (which reproduction will be referred to as xe2x80x9ctime-shift reproductionxe2x80x9d hereinafter).
Nevertheless, in the proposed information recording and reproducing system, reproduction start time is merely shifted and good convenience is not expected. For instance, if a user returns home at 10 p.m. with the reservation of recording a TV program set from 9 p.m. to 11 p.m. and the TV program being recorded is subjected to time-shift reproduction as stated above, then it takes time for reproduction from 10 p.m. to 12 p.m. Due to this, if the user needs to finish watching television by 11 p.m., he or she has to give up reproducing the information halfway.
An object of the present invention object is to provide an information recording and reproducing system for recording and reproducing information on and from a recording medium, characterized in that information is recorded apparently simultaneously with information being reproduced and that, if reproducing the already recorded information, an arbitrary reproduction rate is set to catch up with recording time to thereby provide improved convenience.
According to the present invention, there is provided an information recording and reproducing system having a compression circuit for compressing input information, recording means for recording the compressed information on an optical disc, a reproducing circuit for reproducing information read out from the optical disc, an expansion circuit for expanding the reproduced information, the system comprising, setting means for setting a desired catch-up time at which reproduction started after a start of recording of the input information catches up the recording, detecting means for detecting recording start time, present time and recording end time, determining means for determining a rate of the reproduction necessary to catch up the recording at the set catch-up time based on the detected recording start time, present time, and recording end time, reproducing means for reproducing the recorded information at a determined rate until the set catch-up time.
The reproducing means has means for reproducing the input information in a real time when there is a remaining time between the set catch-up time and the detected recording end time
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.